SetInputChannelGain
input->SetInputChannelGain(0, input->GetInputChannelGain(0) * f);
input->SetInputChannelGain(1, input->GetInputChannelGain(1) * f);
input->SetInputChannelGain(chan, DB_TO_GAIN(static_cast<const float *>(value)[chan]));
input->SetInputChannelGain(0, m * fl);
input->SetInputChannelGain(1, m * fr);
void SetInputChannelGain(int channel, float gain);
input->SetInputChannelGain(i, fInputSetting[index].FindFloat("InputChannelGain", i));